#mIndicator {
    -fx-background-color: rgba(0, 0, 0, 0.5);
}

.thumb-grid-cell #mRoot {
    -fx-border-width: 2;
    -fx-border-color: lightgrey;
}

.thumb-grid-cell:hover #mRoot {
    -fx-border-width: 2;
    -fx-border-color: yellowgreen;
}